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RésuméCette étude visait à explorer l’existence de différences qualitatives et quantitatives en évocation lexicale entre des patients atteints de la maladie de Parkinson (MP) et des sujets contrôles (SC). Un groupe de patients francophones atteints de la MP et un groupe de SC, appariés pour l’âge et le niveau de scolarité, ont effectué une tâche d’évocation lexicale libre ainsi que plusieurs tests neuropsychologiques. Le nombre de mots, la fréquence, la familiarité, la concrétude des mots et la stratégie utilisée lors de l’évocation des mots ont été analysés. Les résultats ont montré que les participants souffrant de la MP produisaient moins de mots que les SC, particulièrement dans la première minute de la tâche d’évocation lexicale libre. Cependant, peu de différences qualitatives ont été observées entre les deux groupes par rapport aux types de mots produits. Des liens semblent exister entre les résultats et les atteintes cognitives du groupe souffrant de la MP. Nous proposons que les déficits d’évocation lexicale observés dans la MP prennent leur origine dans les problèmes exécutifs dont souffrent ces patients.

Time-course and qualitative analysis of unconstrained oral naming abilities in non-demented Parkinson’s individualsThe goal of this study was to provide a quantitative and qualitative analysis of the word production of patients with Parkinson’s disease (PD) and compare it to that of matched control individuals, with an emphasis on the characteristics of the words produced and their correlation with the presence of executive deficits. Semantic and phonological oral naming tests (ONT) are often used to assess cognitive dysfunction in PD. In general, results have shown that patients with PD produce fewer words in both tasks than matched control individuals while the qualitative analyses of word production in PD patients are contradictory. While some studies have shown that the average size of phonemic and semantic clusters are not reduced in PD, others have reported that switching and clustering are decreased in PD patients. These contradictory results could be partially explained by the different evaluation criteria used (semantic and phonologic). In order to minimize this factor, we used an unconstrained oral naming task (UON) where a group of non-demented PD and a group of control individuals, matched for gender, age and education, were invited to produce words within a limited time period (150 second), without having to respect any production criterion. Different aspects of word production were analyzed, such as number of words, frequency, familiarity, concreteness and number of words produced within each 30-second period. Participants also performed a short neuropsychological battery and analysis production was correlated with their profile. Results showed that switching is impaired in PD patients while clustering is not. The results of this qualitative analysis are consistent with the possibility that the oral naming production of Parkinson’s patients reflects a disruption of frontal-basal ganglia circuits mediating set-shifting abilities.